MeC64 is a mechanical replacement keyboard for the Commodore 64 (bread bin model).

Features:

Compatible with the original Commodore 64 motherboard

Diodes on all switches i.e. no ghosting. (The C64 does not seem to benefit)

Light and sturdy mounting plate made of aluminum.

MX Lock switch for caps lock.

Can be easily used as a USB keyboard by adding a controller

When in USB configuration, it supports two digital joysticks

Can control the C64 power LED.

All the flexibility of a programmable controller (e.g. remapping, layers)

Use your great looking C64 double shot keycaps on a Cherry MX switch of your choice

The project

In the beginning of 2012 a nostalgia for the look of the old bread bin Commodore 64 hit me. I wanted to have a computer that is built into the keyboard again, the Amiga 1200 being the latest one. So I bought a broken C64 with the intent of putting a Raspberry PI in it. The bread bin was as cool looking as I remembered it. I really like the brown double shot keycaps with all the strange symbols. I googled and found the Keyrah and both a avr and a pic based DIY project. But I thought it might be fun the make my own keyboard controller and got the idea of making a Arduino shield. I soldered the shield, made a basic firmware and happily started to use the keyboard with my pc.

Arduino shield for connect a C64 keyboard.

The experience was horrible, I needed to really hammer the keys to get them to register, the project started to feel like a failure. The C64 looked great as a nostalgia thing but I could not use the keyboard . Then for some reason I decided that I was not going to give up, I was going to get my retro keyboard not matter what.

I found a cheap mechanical keyboard with Cherry MX red switches and thought that it would be a perfect fit. I like soft switches and they are linear like the switches in the C64. The red switches fitted my memories of the C64 keyboard better the the real thing . So I made a list of what was needed.

Keycap converters

I started with the keycap converters as that seemed to be the hardest thing to make. I made a prototype by gluing a the top of the stem of the C64 keyboard together with a mount of a Cherry type keycap. I tried to make a silicon form and mold copies of the prototype in plastic but it was hard to get an even quality and I only managed to make 1 to 3 that was good enough each day.

Silicone forms filled with plastic resin.

When I got enough converters to try them I found out that my prototype was not completely straight so it did not look very nice.

Test of molded keycap converters.

When I was looking for ways to make a mounting plate I found out about Shapeways and got the idea of 3D printing them so I made a 3D model and it turned out pretty good.

3D printed keycap converters from Shapeways.

Mounting plate

The mounting plate is designed to be the only part needed to hold the keyboard in the case, this is achieved by having bends along the sides with holes for the screws. My first thought was to mill the mounting plate but that just show how much I know about milling and after some tips on Elektronikforumet I understood that water or laser cutting was the way to go if you only want to make a small number. It took a lot of asking around to find a laser cutting company that could also do bending and that was willing to take this job without charging a ridiculous sum for doing it but in the end I found one.

Aluminum mounting plate for.

PCB

Then it was time for the PCB. I thought this would be the easy part but I had only done small PCBs in a paint program before and now I needed a real design tool. It took some time to become friends with KiCad but I managed to make what I wanted and ordered the PCBs. After a month or so I got the PCBs and there was no major design flaws .

I needed custom stabilizers and I found a video on Youtube on how to make them and bought the tool and piano wire.

All the parts before assembly.

The assembling was the most fun part as I got to solder which I really like and see the thing come together. When it was finished the C64 looked exactly as it did before I began (which was the intent) and it felt a little stupid to say “look, I built this!”

Finished MeC64.

Keycaps on.

Backside.

I’m not finished with the firmware but I got the basic functionality working and the keyboard feels great now! I have bought another working C64 with a much better keyboard that registers keys when you press them but I still really don’t like the feel of it.

The reason I did this project was mostly to learn new things and to prove to myself that I could realise an idea and not stop at thinking “I could do this”.

Did you have to modify the case in any way to make the mounting plate fit? Or in other words: Is this mod reversible? So could you mod a C64 to use this keyboard, and mod it back to original afterwards without damage?

I really would feel bad to hurt such a nice thing.

But on the other hand: Now we only need a way to build a case, looking like the old one, which has a mounting option for a Raspberry Pi…

7bit wrote:Did they have a per-hole price? We might end up doing them with more holes than the C64 needs.

I don't think the number of holes is that important for the price, more holes takes a little more machine time but the laser cutter is fast. The overhead of machine setup, invoicing, quotation and shipping for small volume is probably the biggest cost for them. The aluminum should be cheep. The offers I got was a little random like 250€ and 50€ (even though he had not managed to open the design file) but most companies didn't even answer my e-mails. I don't think they make any money of an order like mine but it reduces there costs if they are between orders and sometime people do stuff just to be nice. If the order has some volume so that the company can make some money then I think offers will change hopefully to lower prices

I have used just the mounting plate as a keyboard and I think it's steady enough at least for a small keyboard. The bends makes it stronger. I think a design basted on this concept could make a good looking keyboard. Lets see some design ideas!

Half-Saint wrote:The original C64 keyboard can easily be removed. He built a replacement so he could just take out the new board and put the old one back in.

Thats right, It can be used as a USB keyboard or a replacement keyboard for the original C64 computer.

Half-Saint wrote:How about a teensy based PCB instead of Arduino?

I used Sparkfun ATMEGA32U4 Breakout, a board with the same controller as the Teensy. You can see it in the last picture. It was easier to get hold of in Sweden. I'm not using the Arduino shield any more but it could do the same thing together with a Leonardo.